Checking the roots on a large cork oak

“Whenever I get a new tree I like to repot it at the first ideal opportunity, regardless of whether or not the tree or soil are showing signs of a required repot because that is such an important component to the future of the tree and a complete unknown until you get in there yourself.”

I couldn’t have said it better. Whenever I get a new tree during repotting season, I make sure to repot it right away so I can see exactly what condition the soil and roots are in. And when I get new trees outside of repotting season, I wait – sometimes patiently – until the first opportunity comes along to repot.

The latter was the case with the cork oak below. I acquired last March – just after it had started putting on new growth and too late, by several weeks, to repot that season.

Large cork oak

After taking the tree out of the pot I found lots of good soil – mostly fresh akadama and pumice. After removing the outer layer of soil, however, I found the core of the rootball to be fully broken down and compacted.

I decided to remove a section of this old soil in the front of the tree. It took about an hour to remove all of the old soil in this area.

After removing old soil from the front of the rootball

And here is the cleaned out section from below.

Beneath the trunk

Normally I’m comfortable removing more old soil than this on established trees, but I haven’t done this work on old cork oaks and don’t know how they’ll respond. Depending on how the tree grows over the next year or two, I’ll think about removing another third of the old soil the next time I repot.

The repot also gave me the opportunity to change the front of the tree.

After repotting

Lots of vigorous growth will be needed to adequately thicken the young primary branches. I’ll start feeding the tree in about a month and let it grow until May or June at which point I’ll see if the tree has grown enough to warrant mid-season cutback and wiring.

I am thinking about that too. I recently acquired a Ezo spruce at the Mammoth auction. It has some die back on top. Do you think I should repot or let it be for a year. It was repotted last year at Lake Merritt. Any advice do I take the plunge or wait?